Perhaps you should try some spelling variations:
"modified sphere estimation algorithms" » "modified sphere estimation algorithm", "modified sphere optimization algorithms", "modified sphere optimisation algorithm", "modified pose estimation algorithms"
"modified objective optimizer algorithms" » "modified objective optimized algorithms", "modified objective optimized algorithm", "modified objective optimization algorithms", "modified objective optimal algorithms"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified objective optimizer algorithms") or ("modified sphere estimation algorithms"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified objective optimizer algorithms") OR ("modified sphere estimation algorithms")).
• Removing quotes may allow a broader search: (( modified objective optimizer algorithms ) or ( modified sphere estimation algorithms )).
• Adding a wildcard symbol may retrieve word variants: (("modified objective optimizer algorithms") or ("modified sphere estimation algorithms"))*.